Vfio: Create Msix capability for vfio device

Loop vfio device config register, then find out the msi and msix
pci capability.

both msi and msix need IrqRequestSocket for adding its routing info
into kvm routing table, but vfio device has one IrqRequestSocket only,
and only msi or msix is enabled at runtime, so Arc is used to let msi
and msix share one device IrqRequestSocket.

BUG=chromium:992270
TEST=pass a device with msix capability to guest, and check device msix
function in guest

Change-Id: I008ccd0e98507dc4d587418fbe00aa23029bdbad
Signed-off-by: Xiong Zhang <xiong.y.zhang@intel.corp-partner.google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/1987812
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>

1 files changed, 4 insertions, 1 deletions

diff --git a/devices/src/virtio/virtio_pci_device.rs b/devices/src/virtio/virtio_pci_device.rs
index 4b161d4..c6d6786 100644
--- a/devices/src/virtio/virtio_pci_device.rs
+++ b/devices/src/virtio/virtio_pci_device.rs
@@ -252,7 +252,10 @@ impl VirtioPciDevice {
 
         // One MSI-X vector per queue plus one for configuration changes.
         let msix_num = u16::try_from(num_queues + 1).map_err(|_| sys_util::Error::new(ERANGE))?;
-        let msix_config = Arc::new(Mutex::new(MsixConfig::new(msix_num, msi_device_socket)));
+        let msix_config = Arc::new(Mutex::new(MsixConfig::new(
+            msix_num,
+            Arc::new(msi_device_socket),
+        )));
 
         let config_regs = PciConfiguration::new(
             VIRTIO_PCI_VENDOR_ID,